Lithium-ion batteries are absolutely ubiquitous in consumer devices these days.
They’re in your computer and your phone. They’re in high-end flashlights and cordless tools. You might even have some in your car. As consumer friendly as lithium-ion batteries are, though, it’s important to remember that they’re capable of storing an immense amount of power.
The popular 18650 lithium-ion cellmight look a bit like a standard AA alkaline battery, but the two types of batteries actually have little in common apart from their shapes.
Lithium-ion batteries store so much power that they have a serious downside if they’re not handled safely: they can explode into violent flames that are incredibly difficult to put out. That statement isn’t intended to scare you – battery fires are extremely rare.
It’s important to understand the level of power that you’re dealing with, though, because that provides a powerful incentive to ensure that you always handle your batteries safely – which is exactly what we’re going to cover in this guide.
It's not difficult to avoid lithium-ion battery fires, but proper charging, usage, transportation and storage are crucial. Here’s what you need to know.
Charge Your Batteries According to the Manufacturers’ Instructions
The first thing we’d like to stress in this guide is that when you buy a battery-powered device, you really do need to read the instruction manual because it will always include directions for safe usage. You shouldn’t assume, for instance, that you can safely charge a battery-powered device with any power source that fits.
The wall adapters for many computers and mobile phones, for instance, are often designed to use higher charging amperages that some devices may not support. A lithium-ion device can only support fast chargingif it has the appropriate circuitry to manage the excess heat produced.
Don’t Carry Loose Lithium-Ion Batteries in Your Pocket
Carrying loose batteries in your pocket is one of the most dangerous things that you can do with lithium-ion cells. To know why this is the case, it’s important to understand how a lithium-ion battery works.
The top part of the battery is the positive terminal, and the rest of the battery – that’s the entire metal enclosure – functions as the negative terminal. The battery’s outer plastic shrink wrap is the only thing protecting the enclosure from touching other metal objects, and it’s easily damaged.
If a metal item – like keys, pocket change or another battery – touches a battery’s positive terminal while simultaneously touching any other metal part of the battery, a violent and immediate fire can occur. It goes without saying that the last place where you want a fire to happen is in your pocket.
Many devices – like flashlights and vapes– have removable batteries. If you do need to transport a spare battery, you should carry it in a protective case and not in your pocket.
Recycle or Repair Batteries with Visible Damage
In the section above, we talked about the fragility of a battery’s outer plastic wrapper. The reason why that’s important is because a short circuit can occur if a metal object touches the positive terminal of a battery while also touching its outside metal case.
This can happen even when the battery is installed in a device because the device’s battery compartment could be metal. So, if you have a device with removable batteries, you should examine your batteries periodically to confirm that they’re in good physical condition. If a battery has a torn wrapper, you can re-wrap it.
If a battery has any other form of damage, though – like a dent or a bulge – you’ll need to recycle it because it’s no longer safe to use.
Keep Lithium-Ion Batteries Away from Extreme Temperatures
Keeping a lithium-ion battery away from extreme temperatures – particularly excessive heat – is one of the most important things that you can do to prevent a fire. At temperatures above 265 degrees Fahrenheit, a battery is in serious danger of becoming unstable and venting hot gas.
Although you might think that there’s no way for a battery to reach that temperature during normal use, it’s possible to encounter dangerous heat levels if you charge a battery with an incompatible charger or leave a device in a hot car parked in bright sunlight.
It's also important to keep lithium-ion batteries away from extreme cold. Although this isn’t a safety issue, it is crucial for the long-term health of a battery because cold temperatures will cause a battery’s charge to drain more quickly.
A lithium-ion battery only lasts for about 300-500 charge-discharge cycles before its capacity begins to dramatically decrease, so you’ll want to get the most out of those cycles. For maximum safety and longevity, you should do your best to keep your battery-powered devices in a room-temperature environment.
Know the Capabilities of a Battery Before Using It
Using a device with a removable battery doesn’t just mean that you need to know how to store and transport loose batteries safely – it also means that you’re responsible for choosing your own batteries and need to make sure that the capabilities of your batteries are appropriate for the way you intend to use them.
When you buy a battery, the two specifications that you need to know are its capacity – measured in milliamp-hours or mAh – and its maximum supported discharge rate, which is measured in amps. These specifications have an inverse relationship, which means that a battery with a higher capacity will have a lower maximum discharge rate.
It’s important for you to understand the requirements of your device because some devices like powerful flashlights may not operate safely with batteries that can only operate at low amperages.
Don’t Use Lithium-Ion Batteries in Unintended Ways
One of the most important things to remember about using a device with a removable lithium-ion battery is that every device is designed for a one specific battery configuration and can’t work safely any other way.
This is another case in which reading the instruction manual is absolutely crucial. You shouldn’t stack two batteries in a single-battery device, for instance, even if you’re able to find two smaller cells that somehow fit. Using two batteries in series doubles the voltage, and you need to know that a device is safe for this mode of operation before trying it.
